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1.
J Environ Sci Health B ; 45(6): 578-88, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20661792

RESUMO

Recently, partly due to the increasing carbon consciousness in the electorates and partly due to the imminent introduction of the Australian Government's Carbon Pollution Reduction Scheme (CPRS), estimating carbon footprints is becoming increasingly necessary in agriculture. By taking data from several sources, this study estimates the national greenhouse gas (GHG) emissions from a variety of farm inputs, for the 23 key vegetables crops grown in Australia. For the 121,122 ha of land occupied by vegetable farms, there are 1.1 MtCO(2)e GHG emissions or 9.2 tCO(2)e ha(-1). In total, 65% of total GHG emissions from the vegetable industry are due to electricity use for irrigation and post-harvest on-farm activities, 17% from soil N(2)O emissions due to N fertiliser use, 10% from agrochemicals, 7% through fossils fuels and 1% from on-farm machinery. The top four vegetables (by area), potatoes, lettuce, tomatoes and broccoli account for 29.1%, 7.9%, 5.9% and 7.2% of total GHG emissions from vegetables, respectively. However, the ratio of GHG emissions between the highest and lowest-emitting crops per hectare and per tonne, are different. Therefore, care must be exercised in carbon footprint labelling vegetable products to ensure that the labels reflect carbon emissions on a per tonnage basis.


Assuntos
Poluentes Atmosféricos/análise , Indústria Alimentícia , Gases/análise , Efeito Estufa , Verduras , Poluentes Atmosféricos/química , Poluentes Atmosféricos/metabolismo , Austrália , Carbono/metabolismo , Dióxido de Carbono/análise , Dióxido de Carbono/metabolismo , Gases/química , Gases/metabolismo , Nitrogênio/metabolismo , Óxido Nitroso/análise , Óxido Nitroso/metabolismo , Medição de Risco , Fatores de Tempo
2.
Environ Sci Pollut Res Int ; 23(20): 20553-20566, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27464658

RESUMO

China contributes 23 % of global carbon emissions, of which 26 % originate from the household sector. Due to vast variations in both climatic conditions and the affordability and accessibility of fuels, household carbon emissions (HCEs) differ significantly across China. This study compares HCEs (per person) from urban and rural regions in northern China with their counterparts in southern China. Annual macroeconomic data for the study period 2005 to 2012 were obtained from Chinese government sources, whereas the direct HCEs for different types of fossil fuels were obtained using the IPCC reference approach, and indirect HCEs were calculated by input-output analysis. Results suggest that HCEs from urban areas are higher than those from rural areas. Regardless of the regions, there is a similarity in per person HCEs in urban areas, but the rural areas of northern China had significantly higher HCEs than those from southern China. The reasons for the similarity between urban areas and differences between rural areas and the percentage share of direct and indirect HCEs from different sources are discussed. Similarly, the reasons and solutions to why decarbonising policies are working in urban areas but not in rural areas are discussed.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Carbono/análise , Habitação/normas , População Rural , População Urbana , Dióxido de Carbono/análise , China , Combustíveis Fósseis/análise , Combustíveis Fósseis/economia , Humanos , População Rural/estatística & dados numéricos , População Urbana/estatística & dados numéricos
3.
PLoS One ; 11(10): e0163941, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27749908

RESUMO

The Philippines is one of the most vulnerable countries in the world to the potential impacts of climate change. To fully understand these potential impacts, especially on future hydrological regimes and water resources (2010-2050), 24 river basins located in the major agricultural provinces throughout the Philippines were assessed. Calibrated using existing historical interpolated climate data, the STREAM model was used to assess future river flows derived from three global climate models (BCM2, CNCM3 and MPEH5) under two plausible scenarios (A1B and A2) and then compared with baseline scenarios (20th century). Results predict a general increase in water availability for most parts of the country. For the A1B scenario, CNCM3 and MPEH5 models predict an overall increase in river flows and river flow variability for most basins, with higher flow magnitudes and flow variability, while an increase in peak flow return periods is predicted for the middle and southern parts of the country during the wet season. However, in the north, the prognosis is for an increase in peak flow return periods for both wet and dry seasons. These findings suggest a general increase in water availability for agriculture, however, there is also the increased threat of flooding and enhanced soil erosion throughout the country.


Assuntos
Mudança Climática , Modelos Teóricos , Agricultura , Filipinas , Rios , Estações do Ano , Movimentos da Água , Abastecimento de Água
4.
PeerJ ; 2: e454, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25071984

RESUMO

Aeolian sediment traps are widely used to estimate the total volume of wind-driven sediment transport, but also to study the vertical mass distribution of a saltating sand cloud. The reliability of sediment flux estimations from such measurements are dependent upon the specific configuration of the measurement compartments and the analysis approach used. In this study, we analyse the uncertainty of these measurements by investigating the vertical cumulative distribution and relative sediment flux derived from both wind tunnel and field studies. Vertical flux data was examined using existing data in combination with a newly acquired dataset; comprising meteorological data and sediment fluxes from six different events, using three customized catchers at Ameland beaches in northern Netherlands. Fast-temporal data collected in a wind tunnel shows that the median transport height has a scattered pattern between impact and fluid threshold, that increases linearly with shear velocities above the fluid threshold. For finer sediment, a larger proportion was transported closer to the surface compared to coarser sediment fractions. It was also shown that errors originating from the distribution of sampling compartments, specifically the location of the lowest sediment trap relative to the surface, can be identified using the relative sediment flux. In the field, surface conditions such as surface moisture, surface crusts or frozen surfaces have a more pronounced but localized effect than shear velocity. Uncertainty in aeolian mass flux estimates can be reduced by placing multiple compartments in closer proximity to the surface.

5.
PLoS One ; 9(3): e91115, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24603812

RESUMO

Depending on the amount of aeolian sediment input and dune erosion, dune size and morphology change over time. Since coastal foredunes play an important role in the Dutch coastal defence, it is important to have good insight in the main factors that control these changes. In this paper the temporal variations in foredune erosion and accretion were studied in relation to proxies for aeolian transport potential and storminess using yearly elevation measurements from 1965 to 2012 for six sections of the Dutch coast. Longshore differences in the relative impacts of erosion and accretion were examined in relation to local beach width. The results show that temporal variability in foredune accretion and erosion is highest in narrow beach sections. Here, dune erosion alternates with accretion, with variability displaying strong correlations with yearly values of storminess (maximum sea levels). In wider beach sections, dune erosion is less frequent, with lower temporal variability and stronger correlations with time series of transport potential. In erosion dominated years, eroded volumes decrease from narrow to wider beaches. When accretion dominates, dune-volume changes are relatively constant alongshore. Dune erosion is therefore suggested to control spatial variability in dune-volume changes. On a scale of decades, the volume of foredunes tends to increase more on wider beaches. However, where widths exceed 200 to 300 m, this trend is no longer observed.


Assuntos
Clima , Conservação dos Recursos Naturais , Ecossistema , Geografia , Análise Espaço-Temporal , Países Baixos , Fatores de Tempo
6.
J Environ Sci Health B ; 43(4): 358-63, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18437624

RESUMO

Pig farms are a vital component of rural economies in Australia. However, disposal of effluent leads to many environmental problems. This case study of the Berrybank Farm piggery waste management system in Victoria estimates greenhouse gas (GHG) benefits from three different activities. Analysis reveals that the capturing and combusting of methane from piggery effluent could save between 4859 and 5840 tCO2e yr(-1) of GHG emissions. Similarly, using methane for replacing fuels for electricity generation could save another 800 tCO2e yr(-1)of GHGs. Likewise, by utilizing the biogas wastes to replace inorganic fertilizers there could be a further saving of 1193 to 1375 tCO2e yr(-1) of GHG, depending on the type of fertilizers the waste replaces. Therefore, a well-managed piggery farm with 15,000 pigs could save 6,852 to 8,015 tCO2e yr(-1), which equates to the carbon sequestrated from 6,800 to 8,000 spotted gum trees (age=35 year) in their above plus below-ground biomass. Implementation of similar project in suitable areas in Australia could have significant environmental and financial benefits.


Assuntos
Poluição do Ar/prevenção & controle , Dióxido de Carbono/análise , Efeito Estufa , Metano/análise , Gerenciamento de Resíduos/métodos , Criação de Animais Domésticos/métodos , Animais , Biomassa , Eletricidade , Monitoramento Ambiental/métodos , Eliminação de Resíduos/métodos , Suínos
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